What is the ruling on one who takes his wife back when he has not divorced her, or if there is doubt about it?

If someone takes his wife back without having divorced her, then his taking her back is void and has no effect. If one doubts whether a divorce has occurred, there is no need for him to take her back, as divorce does not occur by doubt, and the original state is the continuation of the marriage, based on the statement of Al-Majd Ibn Taymiyyah: "If one doubts the divorce or its condition, it is built upon the certainty of the marriage." However, if someone doubts the divorce and wishes to be cautious, and takes his wife back, then his taking her back is valid and removes the doubt. Al-Mardawi said: "Piety is to adhere to the divorce. If the doubtful divorce was revocable: he should take his wife back if she had been consummated with." And it is stated in Ibn Rajab's "Al-Qawa'id": "Taking her back in a marriage contract where divorce is doubted... is a valid return that removes the doubt."